Pumping apparatus



Oct. 25, 1932.

E. IINSELLA 1,884,738

PUMPING APPARATUS Filed June 9. 1928 4 Sheets-Sheet l EDWARD KINSELLA I Inventor B 544M 44- y Attorneys Oct. 25, 1932. E. KlNSELLA 1,384,733

PUMPING APPARATUS Filed June 9, 1928 4 Sheets-Sheet 2 E DWARD KI N SBLLA l n ve nto I At't or neys Oct. 25, E KNSELLA PUMPING APPARATUS Filed June 9, 1928 4 Sheets-Sheet 3 EDWARD KINSELLA Inventor Oct. 25, 1932. E, K|N$ELLA 1,884,738

PUMPING APPARATUS Filed June 9, 1928 4 Sheets-Sheet 4 EIWARD KlNSi-ILLA I enter By 1 Attorneys Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE EDWARD KINSELLA, OF SPONDON, NEAR DER-BY, ENGLAND, ASSIGNOR T GELANESE CORPORATION OF AMERICA, A GOIELPORATION OF DELAWARE PUMPING APPARATUS Application filed June 9, 1928, Serial No. 284,128 and in Great Britain February 9, 1928.

This invention relates to new or improved pumping apparatus for delivering artificial silk spinning solutions or other applications, especially such applications as require liquids or solutions to be delivered under pressure with a high degree of regularity.

Pumping apparatus according to the invention comprises one or more pumping units, each of which units comprises a pump, a static measuring device and a pressure balance valve, (the delivery from the pump of the unit being greater than the delivery from the static measuring device) so combined and arranged that the delivery from the pump communicates with the inlet side of the static measuring device through one side of a pressure balance valve the motor member of.

which pressure balance valve is subjected on this side to the pressure of the inlet side of the static measuring device and on the other side to the pressure common to the delivery side of the static measuring device and the spinning jet or jets or other point of use, which motor member carries or is adapted to operate a valve to control the flow of the excess fluid from the delivery side of the pump back to the feed side thereof.

By the term static measuring device I mean an orifice of determined dimensions formed by an orifice in a disc or by a capillary tube, constriction or equivalent device adapted to pass a given or measured volume of fluid by virtue of a given pressure difference as be tween. the inlet side and the outlet side of said device.

Any suitable means may be employed to provide a definite and substantially unvarying pressure difierence across the static measuring device (i. e. between the two sides thereof)irrespective of the pressure required to overcome the resistance of the point of use of the unitand for compensating for the drop 1n pressure occurring in the spmnmg solution or other fluid 1n 1ts passage through .1 the static measuring device, and by this compensation enablm g a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve.

If desired, the pumping unit or each pumping unit may comprise. means adapted to operate under abnormal or excess out-of-balance pressure developing on the delivery side of the static measuring device (due for instance to the spinning jet or ets or other point of use becoming badly choked) and place the delivery side of the static measuring device in communication with the feed side of the pump, thereby releasing the pressure and permitting the fluid to circulate idly in the unit and preventing the unit from delivering the fluid under out-of-balance conditions.

Further, if desired, the pumping unit or each pumping unit may comprise means adapted to operate under abnormal or excess out-of-balance pressure developingonthefeed ide of the static measuring device (due for instance to sticking of the valve member of thepressure balance valve) and place the feed side of the static measuring device in tree communication with the feed side of the pump, thereby, in this case also, releasing the pressure and permitting the fluid to circulate idly in the unit and preventing the unit "from delivering the fluid under out-of-balance conditions.

If desired the means for opening communication between the delivery side of the static measuring device and the feed side of the pump when an abnormal or excess OUiJ-OZE- balance pressure develops on the delivery side of the static measuring device, may themselves be arranged to operate and openfree communication between the inlet side of the static measuring device and the feed side of the pump when an abnormal or excess outoff-balance pressure develops on the inlet side of the static measuring device.

In performing the invention for delivermg cellulose acetate solutions or other solutions or fluids the viscosity of which varies with the temperature, and especially when delivering such solutions in the spinning of artificial silk, I preferably provide in association with the static measuring device a compensating device adapted to act under, variation of temperature to control the orifice of the static measuring device, so that the How through the static measuring device, and hence the delivery from the pumping unit or units so provided, may remain uniform under variations of temperature.

The accompanying drawings serve to illustrate forms of the invention, it being understood that they art given only by way of illustration and are in no way limitative.

Figure 1 shows one form of pumping unit constructed in accordance: with the invention, the form shown comprising a pressurebalance valve (shown in section) of the piston type, the piston of Which operates a slide valve member of the piston type. The form illustrated in this figure also comprises a valve operated by a bi-m-etal strip to control the aperture of the static measuring device, for ensuring uniformity of delivery from the unit under variationsof temperature.

Figure 2 is a detail-view, in section, showing the static measuring device of Figure 1 on a larger scale.

Figure 3 is a similar View to Figure 1, but illustrating a modified form of the pumping unit shown in Figure 1, the piston and slide valve member in this modification being arranged to operate respectively under an abnormal or excess out-of-balance pressure developing on the delivery side of the static measuring device and place the delivery side of said device in communication with the feed side of the pump, and under an abnormal or excess out of balance pressure developing on the feed side of the static measuring device to place the feed side of said device in 'free communication with the feed side of the pump.

Figure 4 illustrates a modified "form of the pumping unit shown in Figure 1, the pressure balance valve in the modification shown in Figure 1 being provided with an auxiliary piston arranged to operate respectively under an abnormal or excess out of-balance pressure developing on the delivery side'of the static measuring device to open communication between the delivery side of said dev vice and the feed side of the pump, and under an abnormal or excess out of balance pressure developing on the feed side of the static measuring device to place the feed side of said device in free communication with the feed side of the pump. 7

Figure 5 illustrates a similar form of pumping unit to that shown in Figure 1. but

' inthe pressure balance valve of the unit shown in Figure 5 the piston is arranged to operate a needle valve member instead of a slide valve member.

Figure 6 illustrates a pumping unit similar to that shown in Figure 5, but in the unit shown in Figure 6 a heavy piston working against gravity is employed in the pressure balance valve instead of a piston working against the pressure of a spring.

Figure 7 illustrates a pumping unit constructed in accordance with the invention,

the form shown comprising a pressure balance valve of the diaphragm type.

The form shown in this figure also comprises a valve operated by a spirit capsule to control the aperture of the static measuring device, for ensuring uniformity of delivery from the unit under variations of temperature.

In Figures 1, 3, 4, 5, 6 and 7 the pressure balance valves of the respective pumping units are shown in section while the pump is represented in elevation.

Figure 8 is a diagrammatic elevation showing apparatus according to the invention applied to a metier or cabinet for the spinning of artificial silk by the dry or evaporative method of formation.

Referring to Figures 1 and 2, 1 is the sup ply pipe leading from the source of supply (not shown in the figure) which source of supply may be any means suitable for supply ng the spinning solution or other fluid under any suitable initial head or pressure to the pumping unit and which may feed one or more pumping units constructed in accordance with Figure 1. 2 indicates the pump of the unit, this pump in the case illustrated be ng of the gear wheel type. 3 is the piston pressure balance valve. 4 is the static measuring device, this device being shown on a larger scale in Figure 2. The casing 5 of the piston pressure balance valve is'formed with two bores of different diameters and has a piston 6 working in the lower and larger bore, which piston carries a hollow slide valve member 7 working in the upper and smaller bore. The casing may, if des red, be bored to a uniform diameter instead of to two different diameters, but I have found the form shown to be advantageous when dealing with artificial silk spinning solutions-or other fluids requiring great sensitivity of control. The piston 6 div des the interior of the casing 5 into an upper chamber 8 and a lower chamber 9, these chambers communicating respectively by the ports 10 and 1.1 with the inlet and the delivery of the static measuring device 4. The upper chamber 8 also communicates via the port 12 with the delivery side of the pump 2; and the said chamber 8 communicates with the supply p pe 1 via the holes 13 in the hollow slide valve member 7 the interior of this member, one or more notches or slots such as 14 in the slide valve member 7, an annular groove 15 in the casing 5, and the port 16 which communicates with the supply pipe 1 and with the inlet to the pump 2. The lower chamber 9 communicates via the port 17 with the spinning jet or jets or other point of use served by the unit. The slide valve member 7 may be provided with any number of notches or slots 14 (one or more) of any suitable shape or form, for instance U shaped or V shaped, and by the positioning of this notch or slot,ornotches or slots, relatively to the annular groove 15, the slide vlave member controls the amount of spinning solution or other fluid by-passcd from the upper chamber 8 (i. e. the delivery side of the pump 2) back to the feed side of the pump 2.

It will be seen that the delivery from the pump 2 communicates with the inlet side of the static measuring device through one side of a piston pressure balance valve the motor member of which (piston 6) is subjected on this side to the pressure of the inlet side of the static measuring device 4 and on the other side to the pressure common to the delivery side of the static measuring device 4 and the spinning jet or jets or other point of use, the motor member (piston 6) operating a valve member (slide valve member 7) to control the flow of excess fluid from the delivery side of the pump back to the feed side of the pump.

The static measuring device (shown on a larger scale in Figure 2) comprises a disc 18 formed with an orfiice 19, which orifice constitutes the true static measuring device. The disc 18 is held between the annular shoulder in the port 11 and the cylindrical cage member 21 (formed with holes 21A), this cage member being pressed against the disc 18 by the screw plug 22.

The isten 6 works against the spring 23, the pressure of this spring serving to establish the desired pressure diiierence across the static measuring device 4, and, by serving to compensate for the drop in pressure occurring in the spinning solution or other fluid in its passage through the static measuring device, enabling a bala cc of pressures to be established against the respective sides of the piston 6.

In normal operation the spinning solution or other fluid passes to the inlet pipe 1 from the source of supply (not shown), for instance from a gear wheel pump, under any suitable init al head or pressure. From the inlet pipe 1 the fluid passes via the port 16 to the pump 2 and from the pump 2 it passes,

under the delivery pressure to which it has been raised by the pump 2, via the port 12 to the upper chamber 8. From the upper chamber 8 a part of the fluid passes via the port 10, through the holes 21A in the cage member 21, the static measuring device 4, the port 11, the lower chamber 9 and the port 17 to the spinning jet or jets or oth r point of use. The surplus fluid from the pump 2 passes from the upper chamber 8 via the holes 13 in the hollow slide valve member 7, the interior of this member, the notch or slot 14, the annular groove 15 in the cas ng 55, and the port 16 back to the feed side of the pump 2.

Should the pressure in the lower chamber 9 rise (due for instance to the point of use becoming partially choked) the piston 6 and slide valve member 7 will move up and restrict the amount of fluid lay-passed back to the feed side of the pump, by restricting the aperture between the notch or slot 14 and the annular groove 15, thus causing the pressure in the upper chamber 8 to rise. The piston 6 and slide valve member 7 to continue to move up until the balance of pressures is restored, the pressures of fluid in both upper and lower chambers being then higher than before.

Conversely, if the pressure in the upper chamber 8 rises (due for instance to the annular groove 15 becoming partially choked) the piston 6 and slide valve member 7 will move down and increase the amount of fluid by-passed back to the feed side of the pump, by increasing the aperture between the notch or slot 14 and the annular groove 15, thus causing the pressure in the upper chamber 8 to fall. The piston 6 and slide valve member 7 continue to move down until the balance of pressures is restored.

So long as the pressures against the piston 6 are equal (i. e. so long as the pressure of fluid in the upper chamber is equal to the pressure of fluid in the lower chamber plus the pressure of the spring 23) the pressure on the delivery side of the static measuring device is always substantially that required to feed the measured quantity oi fluid to the spinning jet or jets or other point of use.

In the form shown in this figure means are provided to ensure constant delivery from the pumping unit under variation of temperature when employing liquids (especially solutions of cellulose acetate or other cellulose derivatives in volatile solvents) the viscosity of which decreases with an increase of temperature. As such means asmall valve 24 operated by a bi-metal strip 25 (for instance a bi-metal strip of brass and iron) is provided to control the orifice 19 of the static measuring device, the valve 24 being fixed to one end of the bimetal strip the other end of which is fixed to the casing 5. Any increase in temperature causes the bi-metal strip 25 to lower the valve 24 to restrict the aperture between t is valve 24 and the orifice 19, and conversely, any decrease in temperature causes the bimetal strip 25 to raise the valve 24 to increase the aperture between the valve 24 and the orifice 19.

The apparatus shown in Figure 1 is provided with a screw plug 26 formed with a channel 27. On first starting up the unit, or on starting up the unit after it has become emptied of fluid, the plug 26 may be unscrewed sufiiciently for the channel 27 to communicate with the atmosphere, thus enabling air in the unit to be displaced by the spinning solution or other fluid, and when lit) screwed down to close the channel 27.

' the pump.

Referring to Fi ure 3, this figure shows a modified form of the pumping unit shown in Figure 1, but the piston and slide valve member are arranged to operate under an abnormal or excess out-of-balance pressure developing on either side of the static-meas uring device and place the side subjected to the out-otbalance pressure in communication with the feed side of the pump. The unit shown in Figure 3 is arranged to oper ate under normal conditions in precisely the same manner as the unit shown in *igure 1 and similar numerals in Figure 3 indicate corresponding parts in Figure 1.

Referring to Figure 3, the bore of the casing is formed with a number of segmental recesses such as 28 in its wall, and the head of the slide valve member is of such length that its upper edge 29 and its lower edge 30 can uncover the annular groove when the piston 6 is moved under abnormal or excess cutoff-balance pressures.

Should an abnormal or excess out-o'f-balance pressure develop on the delivery side of the static measuring device (due for instance to the point of use becoming badly choked) such pressure, acting through the lower chamber 9, will cause the piston 6 and slide valve member 7 to move up suiiiciently for the lower edge of the slide valve member 7 to uncover the annular groove 15 whereby the pressure is relieved from the upper chamber 8 via the annular groove 15 and port 16 to the feed side of the pump. The piston 6 and slide valve member 7 continue to move upwards, (usually more rapidly) after this release of pressure, until the lower edge 31 of the piston 6 uncovers the recesses 28 whereu on the ressure of the l fluid in the lower chamber is released via the recesses 28, upper chamber 8, annular groove 15 and port 16 to the feed side of By these means the fluid is caused to circulate idly in the unit and the unit prevented from delivering the fluid to the point of use until the cause of the outof-balance condition is removed. On removal of the cause of the out-of-balance condition aspring 32 disposed in the space between the slide valve member 7 and the plug 26 returns the slide valve member 7 and piston 6 to their normal positions, this spring being fitted solely for this purpose and being arranged to come into compression only when the piston and slide valve member move up under an abnormal or excess out-of-balance pressure developed in the lower chamber 9.

In the converse case, when an abnormal or excess out-of-balance pressure develops on the inlet side of the static measuring device, such pressure, acting through the upper chamber 8, will cause the p ston 6 to lower the slide valve member 7 suficiently for the upper edge 29 of said member to uncover the annular groove 15, thereby establishing free communication between the feed side of the static measuring device and the feed side of the pump, via the upper chamber 8, the holes 13 in the slide valve member 7, the interior of this member, the annular groove 15 and the port 16. By these means the pressure of the fluid in upper chamber 8 is released and the fluid is caused to circulate idly in the unit, and the unit is prevented from delivering the fluid to the point of use until the cause of the ou -of-balance is removed. On removal of the cause of the out-of-balance condition the piston 6 and the slide valve member are returned to their normal positions by the spring 23.

Referring to Figure 4 this figure shows a modified form of the pumping unit shown in Figure 1, the pressure balance valve in this modified form being provided with an auxiliary piston arranged to operate respectively under an abnormal or excess out-ofbalance pressure developing on the delivery side of the static measuring device to open communication between the delivery side of said device and the feed side of the pump, and under an abnormal or excess out of balance pressure developing on the feed side of the static measuring device to place the feed side of said device in free communication with the feed side of the pump. The pressure balance valve and pump in this unit are constructed in a manner very similar to that of the pumping unit shown in Figure 1, corresponding numerals in Figure 4 indicating corresponding parts in Figure 1, and under normal conditions the unit shown in Fi ure 4 operates in precisely the same manner as the unit shown in Figure 1.

It will be seen that whilst the pumping unit shown in Figure 4 is otherwise similar to that shown in Figure 1, the casing 5 of the pressure balance valve 3 is provided with a second bore in which the auxiliary piston 83 works, the port 10 being extended to communicate with this bore, and a port 34 being provided to communicate between the port 11 and the second bore. The auxiliary piston 33 is subjected on the one side to the pressure of the fluid on the inlet side of the static measuring device (acting through the extended port 10) and on the other side to the pressure of the fluid on the delivery side of the static measuring device (acting through the ports 11 and 34). The auxiliary piston 33 carries two slide valve members 35 and 36 arranged to control the respective ends 37 and 38 of the release port 39, this release port being connected to the pipe 40 which communicates via the T piece 41 with the inlet p.'=pe 1 and hence with the feed side of the pump 2. Springs 42 and 43 are provided to press against the valve members 35 and 36 respectively and small holes 44 and 45 are provided respectively in the valve members and 36. The spring 43 is suitably stronger than the spring 42 (in order to compensate for the drop in pressure occurring in the fluid in its passage through the static measuring device 4 and to enable a balance of pressures to be established against the respective sides of the auxiliary piston 33) and these springs under normal conditions keep the auxiliary piston 33 and its slide valve members and 36 in such position as to keep the ends 3'7 and 38 of the release port 39 closed, thus enabling the pumping unit to function precisely as described with reference to Figure 1.

Should an abnormal or excess out-of-balance pressure develop on the delivery side of the static measuring device (due for instance to the spinning jet or jets or other point of use becoming badly choked) such pressure acting through the ports 11 and 34 will cause the auxiliary piston 33 and its valve members 35 and 36 to move upwards. The first effect of this movement is to uncover the end37 of the port 39 by the lower edge of the valve member 35 whereupon pressure isreleased from the inlet side of the static measuring device 4 via the port 10, the end 37 of the port 39, the pipe and T piece 41 to the inlet pipe 1 and hence with the inlet side of the pump 2. This release of pressure causes the auxiliary piston 33 and its valve members to rise further until the valve member 36 uncovers the end 38 of the port 39 whereupon the pressure of the delivery side of the static measuring device 4 and of the lower chamber 9 is released via the ports 11 and 34, the port 39, the pipe 40 and T piece 41 to the inlet pipe 1 and hence to the feed side of the pump 2. The auxiliary pis ton 33 and its valve members 35, 36 remain in this position and the fluid circulates idly in the unit and the unit ceases to deliver the fluid to the point of use until the cause of the out-of-balancc condition is removedv On removal of the cause of the out-of-balance condition the auxiliary piston 33 and its valve members 35 and 36 are returned to their normal position by the springs 42 and 43 In the converse case, where an abnormal or excess out-of-balance pressure develops on the feed side of the static measuring device, such pressure, acting through the port 10, causes the auxiliary piston 33 and its valve members 35 and 36 to move down. The first effect of this movement is to uncover the end 33 of the port 39 by the upper edge of the valve member 36, thereby releasing the pressure from the delivery side of the static measuring device via the ports 11 and 34, the end 38 of the port 39, the pipe 40 and T piece 41 to the inlet pipe 1, and hence to the inlet side of the pump 2. This release of pressure causes the auxiliary piston 33 and its slide valve members, 35, 36 to move down still further, until the upper edge ofthe valve meinber35 uncovers the upper end 37 of the port 39, thus establishing free communication between the feed side of the static measuring device and the feed side of the pump; via the port 10, the end 37 of the port 39, the pipe 40 and T piece 41 and the inlet pipe 1 to the inlet side of the pump 2, thereby releasing the pressure from the feed side of the static measuring device. The auxiliary piston 33 and its valve members remain in this position and the fluid circulates idly in the unit and the unit ceases to deliver the fluid to the point of use until the cause of the out-of-balance condition is removed. On removal of the cause of the out-of-balance condition the auxiliary piston 33 and its valve members 35 and 36 are returned to their normal position by the springs 42 and 43.

Referring to Figure 5, whilst the pumping unit shown in this figure is otherwise similar in construction and operation to that shown in Figure 1 (similar numerals in Figure 5 indicating corresponding parts in Figure 1) the piston 6 in Figure 5 is arranged to operate a needle valve member 46 which, by con trolling the throat 47, controls the flow of excess fluidfrom the upper chamber 8 (i. e. the inlet side of the static measuring device 4) back to the port 16 and the feed side of the pump 2.

Referring to Figure 6, this figure shows a form of pumping unit very similarin construction and operation to that shown in Figure 5, but in which the motor member is a heavy piston working against the force of gravity instead of a piston working against the pressure of a spring; and similar numerals in Figure 6 indicate corresponding parts in Figure 5. The piston 6 in Figure 6 is made of such weight that its weight serves to establish the desired pressure difference across the static measuring device and compensate for the drop in pressure occurring in the fluid in its passage through the static measuring device. In passing itwill be understood that the pumping unit shown in Figure 6 must be arranged to operate substantially in the position shown, and will be inoperative if inverted or employed in a horizontal position. 1

Referring to Figure 7, this figure shows a pumping unit similar in construction and operation to that shown in Figures l and 2 (similar numerals in Figure 7 indicating corresponding parts in Figures 1 and 2). In Figure 7, however, the pressure balance valve is of the diaphragm type, the diaphragm 105 being arranged to operate the needle valve member 110, which member, by controlling the throat 112, controls the flow of excess fluid from the upper chamber 8 (i. e. inlet side of the static measuring device) back to the port 16 and feed side of the pump 2.

In the form shown in Figure 7 means are provided to ensure constant delivery from the pumping unit under variation of temperature when employing liquids (especially solutions of cellulose acetate or other cellulose derivatives in volatile solvents) the viscosity of which decreases with an increase of temperature. As such means a small valve member 118 operated by the collapsible metal capsule 119 is provided to control the orifice 19 of the static measuring device. The valve member 118 is fixed to the metal capsule 119 which contains a quantity of parafiin oil, methylated spirit, ether or other suitable liquid, the capsule 119 being fixed to the p threaded rod 120 passing through the screw plug 121 in the casing 5. By adjusting the nut 122 and the lock nut 123 the position of the valve member 118 may be adjusted or set relatively to the orifice 19. The valve member 118 is also fitted to or'formed with i a rod 124 which is fitted to a diaphragm 125,

which diaphragm is exposed on the one side to the pressure of the atmosphere and on the other side to the pressure of the fluid in the chamber 115, the diaphragm 125 thereby serving to obviate operation of the valve member 118 under changes of pressure in the fluid. Should the temperature of the fluid in the pumping unit increase, the metal capsule 119 is expanded by the liquid contained therein and moves the valve member 118 to restrict pumping units similarly connected to the header 1, these pumping units in the case illustrated being constructed and arranged to operate precisely as described with refer 'ence to Figure 3.

The spinning solution passes from the source of supply under any suitable initial heador pressure via the header or supply pipe 1 to the branch pipes 3, 3a and thence respectively through the pumping units (in the manner described with reference to Figure 3) to the spinning jets 4, 4a served by the respective pumping units, these jets extrud-.

ing the solution into the spinning metier or cabinet 5 where the artificial silk filaments are formed by the evaporation of thevolatile solvent in the known manner.

Should an abnormal or excess out-of balance pressure develop on either side of the 'static measuring device of the one or any of the pumpingunits, such pressure will operate, in the mannerdescribed with reference to Figure 8, to place the side subjected to i such pressure in communication with the feed side of the pump of the unit, and the delivery from the pumping unit subjected to such pressure will cease until the cause of the outof-balance condition is removed.

As is known, in the spinning of artificial silk the spinning solution is usually extruded through the spinning jets under very high pressures, and it will be understood that in applying the apparatus of the present invention to the spinning of artificial silk the spining solution may be fed to the pumping unit or units under any suitable head or pressure lower than the delivery pressure of the pump (or pumps) of the unit (or units).

What I claim and desire to secure by Letters Patent is 1. Pumping apparatus for delivering artificial silk spinning solutions or other fluids, comprising at least one pumping unit itself comprising a pump, a measuring device having delivery means, the delivery from the pump being greater than the delivery from the measuring device and the delivery side or" the pump communicating with the feed side of the measuring device, a pressure balance valve comprising (a) a motor member subjected 011 the one side to the pressure of the feed side 01": the measuring device and on the other side to the pressure of the delivery side of the measuring device and to the pressure of the delivery from the pumping unit, and (b) a valve member operatively connected to said motor member, a communication between the feed side of the measuring de vice and the feed side of the pump controlled by said valve member and serving to by-pass the excess fluid from the feed side of the measuring device back to the feed side of the pump, and means for establishing a given pressure difference across the measuring device and for compensating for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve.

2. Pumping apparatus for delivering artificial silk spinning solutions or other fluids comprising at least one pumping unit itself comprising apump, a. static measuring device, being an orifice of determined dimensions, said measuring device having delivery means, the delivery from the pump being greater than the delivery from the static static measuring device and the feed side of the pump controlled by said valve member and serving to by pass the excess fluid from the feed side of the static measuring device back to the feed side of the pump, and means for establishing a given pressure difference across the static measuring device and for compensating for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve, said pumping unit further comprising means adapted to operate under an excess out of balance pressure developing on the delivery side of the static measuring device to place the delivery side of the said device in communication with the feed side of the pump, thereby releasing the pressure and permit" ting the fluid to circulate idly in the pump ing unit and preventing said unit from delivery under out of balance condit ons.

3. Pumping apparatus for delivering artilicial sill; spinning solutions or other liuids comprising at least one pumping unit itself comprising a pump, a static measuring device, being an orifice of determined dimensions, said measuring device having delivery means, the delivery from the pump being greater than the delivery from the static measuring device and the delivery side of the pump communicating with the feed side of the static measuring device, a pressure balan valve comprising (a) a motor member subjected on the one side to the pressure of the feed side of the static measuring device and on the other side to the pressure of the delivery side of the static measuring device and to the pressure of the delivery from the pump 'ing unit, and (b) a valve member operatively connected to said motor member, a COl11111llnlcation between the feed side of the static measuring device and the feed side of the v pump controlled by said valve member and serving to by-pass the excess fluid from the feed side of the static measuring device back to the feed side of the pump, and means for establishing a given pressure diil'erence across the static measuring device and for compensating for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established 011 the respective sides of the motor member of the pressure balance valve; said pumping unit further comprises means adapted to operate under an excess out of balance pressure developing on the delivery side of the static measuring device to place the delivery side of said device in communication with the feed side of the pump, and means adapted to operate under an excess out of balance pressure developing on the feed side of the static measuring device to place the teed side of said device in free communication with the feed side of the pump, thereby,

in each case, releasing the pressure and permitting the fluid to circulate idly in the pumping unit and preventing said unit from delivering under out of balance conditions.

l. Pumping apparatus for delivering artii'icial sillr spinning solutions or other fluids comprising at least one pumping unit itself comprising a pump, a static measuring de vice containing an aperture, the delivery from the pump being greater than the delivery from the static measuring device and the delivery side of the pump communicating with the feed side of the static measuring device, a pressure balance valve comprising (a) a motor member subjec'ed on the one side to the pressure of the feed side of the static measuring device and on the other side to the pressure of the delivery side of the static measuring device and to the pressure of the delivery from the pumping unit, and (b) a valve member operatively connected to said motor member, a communication between the feed side of the static measuring device and the feed side of the pump controlled by said valve member and serving to by-pass the excess fluid from the teed side of the static measuring device back to the feed side of the pump, and means for establishing a given pressure difference across the static measurng device and for compensating for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve; said pumping unit further comprising a compensating device adapted to operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow through said measuring device under variations of temperature.

5. Pumping apparatus according to claim and comprising as said compensating device a valve member controlling the aperture of the static measuring device, and a bi-metal strip see red on the one end and carrying said valve member on the other end.

6. Pumping apparatus according to claim 1 comprising as the means for establishing a given pressure diii'erence across the static measuring device and for compensating for the drop in pressure or the fluid in its pasthrough said device, a spring acting upon the motor member of the pressure balance valve,

7. Pumping apparatus according to claim 1, comprising, as the means for establishing a given pressure diii'erence across the static measuring device and for compensating for the drop in pressure of the fluid and its passage through said device, a spring acting upon the motor member of the pressure balance valve, said spring being arrai'iged to press against the said motor member on the side thereof subjected to the pressure of the detill livery side of the static measuring device.

8. Pumping apparatus according to claim 2 and comprising, as the means adapted to operate under any excess out of balance pressure developing 011 the delivery side of the static measuring device to place the delivery side of said device in communication with the feed side of the pump, means comprising a piston subjected on its respective opposite sides to the pressure of the feed side of the static measuring device and to the pressure of the delivery side of said device, means for compensating for the normal drop in pres sure of the fluid in its passage through the static measuring device thereby enabling a balance of pressures to be established on the respective sides of said piston under normal conditions, a communication between the delivery side of the static measuring device and the feed side of the pump, the said piston being arranged to keep said communication closed under normal conditions and to open the same when actuated by an excess out of balance pressure on the delivery side of the static measuring device.

9. Pumping apparatus according to claim 3 and comprising, as the means adapted to operate under an excess out of balance pressure developing on the delivery side of the static measuring device and as the means adapted to operate under an excess out of balance pressure developing on the feed side of the static measuring device, means comprising a piston subject-ed on its respective opposite sides to the pressure of the feed side of the static measuring device and to the pressure of the delivery side of said device, means for compensating for the normal drop in pressure of the fluid in its passage through the static measuring device thereby enabling a balance of pressures to be established on the respective sides or" said piston under normal conditions, acommunication between the delivery side of the static measuring device and the feed side of the pump, said piston being arranged to keep said communications closed under normal conditions and to open said communication when actuated under an excess out of balance pressure on the delivery side of the static measuring device, and a communication between the feed side 'ofthe static measuring device and the feed side of the pump, said piston being arranged to keep said communication at least partially closed under normal conditions and to open said communication freely when actuated under an excess out of balance pressure developing on the feed side of the static measuring device. 7

l0. Pumping apparatus for delivering artificial sitk spinning solutions or other fluids comprising at least one pumping unit itself comprising a pump, a static measuring device being an orifice of determined dimensions, the delivery from the pump being greater than the delivery from the static measuring device and the delivery side or" the pump communicating with the feed side of the static measuring device, a pressure balance valve comprising a piston'motor member subjected on the one sideto the pressure of the feed side of the static measuring device and on the other side to the pressure of the delivery side of the static measuring device and to the pressure of the delivery from the pumping unit, and (b) a slide valve member operatively connected to said piston motor member, a communication between the feed side of the static measuring device and the feed side of the pump controlled by said slide valve member and serving to by-pass the excess fluid from the feed side of the static measuring device back to the feed side of the pump, a spring acting upon the piston motor member of: the pressure balance valveby pressing against said motor member. on the side thereof subjected to the pressure of the delivery side of the static measuring device, said spring serving to establish a given pressure difference across the static measuring device and to compensate for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the piston motor member of the pressure balance valve; said pumping unit further comprising means adapted to operate under an excess out of balance pressure developing on the delivery side of the static measuring device to place the delivery side of said device in communication with the feed side of the pump, and means adapted to operate under an excess out of balance pressure developing on the feed side of the static measuring device to place the feed side of said device in free communication with the feed side of the pump thereby, in each case, releasing the pressure and permitting the fluid to circulate idly in the pumping unit and preventing said unit from delivering under out of balance conditions.

11. Pumping apparatus for delivering artificial silk spinning solutions or other fluids, comprising at least one pumpingunit itself comprising a pump, a static measuring device being an orifice of determined dimensions, the delivery from the pump being greater than the delivery from the static measuring device and the delivery side of the pump communicating with the feed side of the static measuring device, a pressure balance valve comprlsing (a) a piston motor member sub ected on the one side to the pressure of the feed side of the static measuring device and on the other side of the pressure of the delivery side 01" the static measuring device and to the pressure of the delivery from the pumping unit,

and (b) a slide valve member operatively connected to said piston motor member, a communication between the feed side of the static measuring device and the feed side of the pump controlled by said slide valve memher and partially closed thereby under normal conditions of operation and serving to bypass the excess fluid from the feed side of the static measuring device back to the feed side of the pump, said slide valve member being arranged to open said communication freely when actuated by the piston motor member under an excess out of balance pressure developing on the feed side of the static measuring device and thereby release the pressure and cause the fluid to circulate idly in the pumping unit thus preventing the unit from delivering under out of balance conditions, a spring acting upon the piston motor member of the pressure balance valve by pressing against said motor member on the side thereof subjected to the pressure of the delivery side of the static measuring device, said spring serving to establish a given pressure difference across the static measuring device and to compensate for the drop in pressure of the fluid in its passage through the said device, thereby enabling a balance of pressures to be established on the respective sides of the piston motor member of the pressure balance valve, said pumping unit further comprising a communication between the delivery side of the static measuring device and the feed side of the pump controlled by the piston motor member of the pressure balance valve and kept closed thereby under normal conditions, the piston motor member and slide valve member of the pressure balance valve being arranged to open said communication under an excess out of balance pressure developing on the delivery side of the static measuring device thereby releasing the pressure and causing the fluid to circulate idly in the unit and preventing the unit from delivering under out of balance conditions.

12. Pumping apparatus according to claim 11 and wherein said pumping unit further comprises a compensating device adapted to operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow through said device under variations of temperature.

13. Pumping apparatus according to claim 11 and wherein said pumping unit further comprises a compensating device adapted to operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow through said device under variations of temperature, said compensating device comprising a valve member controlling the aperture of the static measuring device and a bi-metal strip secured on the one end and carrying said valve member on the other end.

In testimony whereof I have hereunto subscribed my name.

EDWARD KINSELLA. 

